Technical Field
The present invention relates to technologies regarding diesel engines.
Background Art
Conventionally, there have been known diesel engines in which fuel is injected into a combustion chamber provided on the upper surface of a piston, and the fuel is combusted in the combustion chamber. These diesel engines include an accumulator fuel injection device (hereinafter referred to as “common rail system”) in which injection patterns can be freely set. The common rail system is constituted by a supply pump that feeds the fuel under pressure, a rail that stores high-pressure fuel, and an injector that injects the fuel (for example, see Patent Literature 1).
Incidentally, these diesel engines are designed in consideration of maintainability. This is because the diesel engines can maintain their performance through implementation of periodical maintenance. However, regarding the supply pump, a pump gear is fixed on the drive shaft of the supply pump, so that the supply pump cannot be detached unless the pump gear is removed. Accordingly, structure, in which the supply pump can be detached without removing the pump gear, has been demanded.
Also, it is important to simplify and streamline processes carried out by an operator, in order to improve the maintainability. Accordingly, structure, which allows the operator to carry out the operations from a constant direction without movement during implementation of maintenance, has been demanded. Furthermore, when the supply pump is mounted, it is essential to include a process for verifying the position of the engagement of gears. Accordingly, structure capable of easily carrying out the above-mentioned process has been demanded.
Also, the diesel engine is designed in consideration of miniaturization. This is because the degree of freedom in terms of design for a vehicle, in which the diesel engine is mounted, is improved by the miniaturization of the diesel engine. Moreover, a tractor is characterized in that the overall width of an engine room is narrow, in order to secure the visibility of front wheels. Accordingly, structure capable of solving the above-mentioned problem and narrowing the overall width has been demanded.
Also, regarding conventional diesel engines, a cam gear is arranged on the side of the front surface of the diesel engine. Then, a cam angle sensor, which is a cam angle detection means, is contiguously arranged on the outer circumferential side of a pulser mounted on the cam gear. The cam angle sensor is configured to output a cam angle (rotation angle) signal every time a portion to be detected on the pulser passes the close vicinity (for example, see Patent Literature 2).
However, when the pulser is mounted on the cam gear and contiguously arranged in close vicinity of the cam angle sensor, and the cam gear is constituted by a helical gear, it is likely that the cam gear is pushed out, which often causes an error in the distance between the cam angle sensor and the pulser. Accordingly, there is a case where the cam angle cannot be accurately measured. Further, there is also a case where a position, at which the cam angle sensor is arranged, causes only the cam angle sensor to protrude forward with respect to another component, which leads to an increase in size.
PTL 1: Japanese Unexamined Patent Application Publication No. 2011-12573
PTL 2: Japanese Unexamined Patent Application Publication No. 2011-231734